<template>
    <div class="search-form">

        <!-- 头部tab切换 -->
        <el-row type="flex" class="search-tab">
            <span v-for="(item, index) in tabs" :key="index"
            @click="handleSearchTab(item, index)"
            :class="{active: index === currentTab}">
                <i :class="item.icon"></i>{{item.name}}
            </span>
        </el-row>

        <el-form class="search-form-content" ref="form" label-width="80px">
            <el-form-item label="出发城市">
                <!-- fetch-suggestions 返回输入建议的方法 -->
                <!-- select 点击选中建议项时触发 -->
                <el-autocomplete
                :fetch-suggestions="queryDepartSearch"
                placeholder="请搜索出发城市"
                @select="handleDepartSelect"
                class="el-autocomplete"
                v-model="form.departCity"
                :trigger-on-focus="false"
                :highlight-first-item="true"
                ></el-autocomplete>
            </el-form-item>

            <el-form-item label="到达城市">
                <el-autocomplete
                :fetch-suggestions="queryDestSearch"
                placeholder="请搜索到达城市"
                @select="handleDestSelect"
                class="el-autocomplete"
                v-model="form.destCity"
                :trigger-on-focus="false"
                :highlight-first-item="true"
                ></el-autocomplete>
            </el-form-item>

            <el-form-item label="出发时间">
                <!-- change 用户确认选择日期时触发 -->
                <el-date-picker type="date" 
                placeholder="请选择日期" 
                style="width: 100%;"
                value-format="yyyy-MM-dd"
                v-model="form.departDate"
                :picker-options="{disabledDate}">
                </el-date-picker>
            </el-form-item>

            <el-form-item label="">
                <el-button style="width:100%;" 
                type="primary" 
                icon="el-icon-search"
                @click="handleSubmit">
                    搜索
                </el-button>
            </el-form-item>

            <div class="reverse">
                <span @click="handleReverse">换</span>
            </div>
        </el-form>  
      </div>
</template>

<script>
import {airsCity} from './air'
export default {
    data(){
        return {
            tabs: [
                {icon: "iconfont icondancheng", name: "单程"},
                {icon: "iconfont iconshuangxiang", name: "往返"}
            ],
            currentTab: 0,
            form:{
              departCity:'',
              departCode:'',
              destCity:'',
              destCode:'',
              departDate:''
            }
        }
    },
    methods: {
        disabledDate(time){
          return time.getTime() < Date.now() - 24*60*60*1000
        },
        async init(name){
          const res = await airsCity(name)
          if(res){
            let cities = res.data.data.filter(city=>{
              return city.sort
              })
              .map(city=>{
              return {
                ...city,
                value:city.name.replace('市','')
              }
            })
            // 上面的链式调用其实就是在 cities 里面过滤了数据
            // 相当于下面的写法
            // cities = cities.filter(city=>{
            //   return city.sort
            // })
            return cities.length == 0 ? [{value:'没有搜索的城市'}] : cities
          }
        },
        // tab切换时触发
        handleSearchTab(item, index){
            // this.currentTab = index
            if(index == 1){
              this.$message('暂时只支持单程机票搜索')
            }
        },
        
        // 出发城市输入框获得焦点时触发
        // value 是选中的值，showList是回调函数，接收要展示的列表
        async queryDepartSearch(value, showList){
          const cities = await this.init(value)
          // 默认将第一项的代码放入 form 表单当中
          // 不用担心用户之后的操作,
          // 如果用户不选择, 默认就有 code 
          // 如果用户选择一个城市, 
          // 会后续触发 select 事件
          // 用户选择的数据会覆盖掉默认数据
          this.form.departCode = cities[0].sort
          showList(cities)
        },

        // 目标城市输入框获得焦点时触发
        // value 是选中的值，showList是回调函数，接收要展示的列表
        async queryDestSearch(value, showList){
          const cities = await this.init(value)
          this.form.destCode = cities[0].sort
          showList(cities)
        },
      
        // 出发城市下拉选择时触发
        handleDepartSelect(item) {
          // 每当选中一个城市, 需要把当前代码添加到 form 当中
          // 虽然用户看不见, 但是我们发请求要用
          this.form.departCode = item.sort
        },

        // 目标城市下拉选择时触发
        handleDestSelect(item) {
          this.form.destCode = item.sort
        },

        // 确认选择日期时触发
        handleDate(value){
          
        },

        // 触发和目标城市切换时触发
        handleReverse(){
          // 要将出发城市和出发代码跟到城市到达代码互换
          const oldDepartCode = this.form.departCode
          const oldDepartCity = this.form.departCity

          this.form.departCode = this.form.destCode
          this.form.destCode = oldDepartCode

          this.form.departCity = this.form.destCity
          this.form.destCity = oldDepartCity
        },

        // 提交表单是触发
        handleSubmit(){
          console.log(this.form);
          //   跳转到所搜结果之前, 需要先进行历史数据储存
          this.$store.commit('historystore/addHistory',this.form)
          this.$router.push({
            path:'/air/flights',
            query:this.form
          })
        }
    },
    mounted() {
      
    }
}
</script>

<style scoped lang="less">
.search-form{
    border:1px #ddd solid;
    border-top:none;
    width:360px;
    height:350px;
    box-sizing: border-box;
}

.search-tab{
  span{
    display: block;
    flex:1;
    text-align: center;
    height:48px;
    line-height: 42px;
    box-sizing: border-box;
    border-top:3px #eee solid;
    background:#eee;
  }

  .active{
    border-top-color: orange;
    background:#fff;
  }

  i{
    margin-right:5px;
    font-size: 18px;

    &:first-child{
      font-size:16px;
    }
  }
}

.search-form-content{
  padding:15px 50px 15px 15px;
  position: relative;

  .el-autocomplete{
    width: 100%;
  }
}

.reverse{
  position:absolute;
  top: 35px;
  right:15px;

  &:after,&:before{
      display: block;
      content: "";
      position: absolute;
      left:-35px;
      width:25px;
      height:1px;
      background:#ccc;
  }

  &:after{
      top:0;
    }

    &:before{
      top:60px;
    }

  span{
    display: block;
    position:absolute;
    top: 20px;
    right:0;
    font-size:12px;
    background: #999;
    color:#fff;
    width:20px;
    height:20px;
    line-height: 18px;
    text-align: center;
    border-radius: 2px;
    cursor: pointer;

    &:after,&:before{
      display: block;
      content: "";
      position: absolute;
      left:10px;
      width:1px;
      height:20px;
      background:#ccc;
    }

    &:after{
      top:-20px;
    }

    &:before{
      top:20px;
    }
  }
}
</style>